Recently, our friend Boc Kron built Mr. Trau Kod (shown above) to protect the reservoir and embankment. It was explained to me that Cambodian people believe there are spirits for all elements such as earth, wind, clouds, etc. and Mr. Trau Kod was built to represent the spirit of the reservoir. This spirit is meant to protect the area and seek revenge on anyone that would harm the reservoir. I think we will still need to implement our inspection and maintenance program after the project is completed but it's comforting to know we have Mr. Trau Kod on our side.
Once this platform is complete we can cut the key into the base and begin filling and compacting the new soil.
we spent an afternoon fabricating a 12’ long, 2” diameter split spoon tube out of a pvc pipe cut longitudinally in half, then banded together with steel bands. the split spoon would core a sample of the soil by being probed into the ground using the bucket of the excavator to drive it down. we were uncertain if the pipe would be strong enough to probe through the unknown soil conditions, so we simply just had to take the risk. we invested a lot of sweat equity, and passion, into the creation, and joked that if the pipe were to simply burst into pieces during use, we would cry, “Stella….!!!!”, to express the pain of our loss.
Well, unfortunately, we hit a tough clay layer where Stella started to buckle under pressure. We weren’t able to probe any further than 0.25m when we started to hear a lot of cracking in the pipe. But, the good news is, the clay layer was a good discovery, as we had assumed worst soil conditions during design. We verified the clay layer by using the excavator to dig a ~10’ deep test pit, upon which we discovered a 1m layer of clay at the surface. Stella was demoted to being used as a measuring stick when taking photos of these test pits.
it took about a week and a half to excavate a portion of the main embankment for the proposed watergate location. the excavation is approx. 20m wide, and 3.5m high.
this location was chosen because the soil conditions at the existing breach (not pictured) is unknown, and consolidation and stabilization of that soil would require surcharging over an extended period of time. instead of building the watergate at that breach, a new location was proposed with the assumption that the soil which it is founded on will already be well consolidated over a number of years by the existing embankment.
Part of our design was to specify the use of a sheepsfoot roller for the soil compaction on the embankment. Narith assured us that it would not be a problem to obtain one here in Siem Reap. However, when we made the deal with the equipment owner they mentioned that their one sheepsfoot roller was already rented but they could provide us with a sheepsfoot tow.
The sheepsfoot tow was definitely inferior to a full sheepsfoot roller and on top of that, the flat drum roller they sent out to pull this thing was older than me and broke down after a week.
Finally, after some tough negotiations, we were able to get a Self-Propelled Tamping Roller and this thing is a beast. You can feel the earth shake when it rolls by. This is a relatively rare piece of equipment so if it breaks down we could be in big trouble but for now it looks like we are in pretty good shape.
Bryse, Chai, and I paid a visit to the concrete mixing plant (CPAC) in Siem Reap (there’s only one plant in this town) to see what facilities were available. Their testing room was quite impressive, they had three compression machines; one for low range testing (such as smaller concrete samples, or compacted soil samples), a high range 350kips machine for the standard 6"x12" cylinders, and a small scale two point loading machine to test unreinforced beams.
Perhaps by saying impressive, I really mean to say I’ve wrongfully assumed such a facility would not have been available here in Siem Reap, or at least would not have been fully equipped with comparable standardized machinery. But I stand corrected, and once again, am proven wrong for underestimating what this town can provide. During the prime stages of the project, we’ve considered perhaps sending samples to
Human Translation had been working with the District Government, the local community, and the Met Sin to resolve this issue. The District Government obtained a letter with Met Sin's thumb print stating that he agreed to move, the local Village Chiefs agreed to collect rice from the villagers benefiting from this project to donate as compensation, and HT has continued to communicate with him to make sure he understood our plan and he felt he was being treated fair.
1. Use an existing community system rather than trying to create a new one
2. Work with strong local leaders that you trust
3. Try to avoid involving cash transactions
4. Keep it simple
One of our goals is to measure the impact of our project over the next few years. We hope that this project will provide many indirect benefits to the community but the main direct benefit we are working towards is an increase in the rice crop yield. It took a few weeks but the Prasat Bakakong District government was able to provide us with the Balang Commune rice yields for the past few years. As you can see from the graph above, the rice yield for Balang is below average for Cambodia and Cambodia is quite a bit below average for Asia.
Brian, a new friend to the project, was brave enough to volunteer to be the rod man on the day we had to survey the river bed for the group back in New York. He told us he wasn't worried about leach bites but we were all glad to see he didn't have any friends attached when he got out of the river.
In additional to helping EWB obtain some valuable data Brian was also afternoon entertainment for some of the local villagers.
The Cambodian dry season is only five months long, from about November to March. So we decided to begin construction November 1st to give ourselves the longest time possible in case of delays or other issues. However, the river flow is still at its highest right now so we had to come up with a solution for crossing the river with our heavy construction equipment. Narith proposed installing a concrete culvert as a temporary river crossing.
It took about two and a half days to set the culverts, place the soil on top and divert the stream but our new path across the river works very well and the equipment has had no problems crossing.
Shannon Flanagan and Christina Ho of the EWB New York Chapter have been working very hard to create an Educational Outreach arm for the chapter. One of their recent initiatives was to collaborate with the Junior Engineering Technical Society or JETS to create lesson plans based on an EWB Project and they were nice enough to use the Cambodia project for their first project! They did a pretty amazing job and it's really interesting to check out the lesson plans.
We had a community meeting at Trau Kod with HRND and some of the commune and village leaders last weekend. Human Translation and HRND wanted to let the community know that we are starting construction and we intend to finish before the next rainy season.
There are still quite a few community issues such as the Water User Group, land merchants from Siem Reap purchasing land within the reservoir basin and a farmer still living on the embankment so we also tried to let everyone know that this is a community project and we are only here to help facilitate resolutions to the issues. We are not here to make decisions for the community. The general tone of the meeting seemed positive although 99% of it was spoken in Khmer so it was tough to tell. For the most part, Tobias and I just tried to look interested and then laugh when it appeared a funny joke had been told.
The equipment finally made it to the site and the embankment repair work has begun! The bulldozer will be working on vegetation clearing and erosion damage removal for the next few days but next week we will begin placing and compacting soil.
This is a photo of the site office being constructed. Work will be taking place from 7:00am to 5:00pm, 7 days a week so we are going to try and make things a bit more comfortable.
Last Thursday we began moving the equipment to Trau Kod. It takes a little over an hour to get to the site from Siem Reap and that is due, in large part, to the last 5km of dirt road through Kroper Village. So our plan was to unload the equipment from their tailors and repair the road as we went so the concrete trucks will have an easier time traveling to the site. The majority of the repair work was just filling holes and moving vegetation that has encroached on the road. However, there was one wood bridge that was completely unsuitable for heaving equipment.
So Narith directed the equipment operators to demolish the wood bridge, back fill soil into the river, dig a trench, and install a concrete culvert.
The photograph above is of the audience that came to watch the bridge demolition and culvert installation. It was quite an operation but the villagers seemed very excited about the improvement to their road.
Last week I attended one of Narith's construction training sessions. Narith has been providing construction training to members of all of the Balang commune villages interested in working on the Trau Kod project since the beginning of the rainy season. The session was held in a small building next to the Balang Police Station where we met with the Commune Chief and the Prom Kod Chief, the man that hosted us when we stayed over night in village on our last trip.
The villagers in attendance that day were "group leaders" or foremen that will be in charge of small groups. Narith's sessions have reviewed the project scope, the project location, construction safety, construction techniques, etc. Most have had experience working as carpenters and masons in Siem Reap and seemed rather bored with Narith's lesson but the benefits of these sessions will probably be very valuable for the group and for the project when we start construction tomorrow.
thanks to Maria and Linda for their tremendous efforts in organizing the bar night fundraiser event. friends and colleagues came and supported, helping raise over $1100! with a match from the PB Foundation, that brings us to over $2200! linda and maria
After traveling for what felt like a week, I finally was able to go back to the site Thursday morning with Chai and Narith. We spent almost every day at Trau Kod on our last trip but seeing the size of the embankment and future reservoir basin again still amazed me. I also saw my first leach in the O Ta Bet river which was kind of terrifying.
The plan is start moving the heavy equipment back to the site next week, begin the embankment repair the following week then the water gate in about a month. There is a lot of work to be done but I think everyone is excited to begin.
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Today is my last day in New York! I'm heading back to Siem Reap for a few months to help start up construction. In the past couple of weeks I've been spending a lot of time with friends, eating a lot of pizza and trying to enjoy the city before leaving. It's certainly exciting to be going back and it's really excited that we are getting so close to construction but I'm going to miss New York.
Every little information helps. One can quickly see how impossible it is to survey every square inch of a 160 acre open field (not to mention, the danger of potential landmines). But after compiling all of the any little surveying that has been done, the hydro team was able to produce a projected topography map using AutoCadd. Ryan spent the weekend shading in the proposed embankment location (solid orange), the estimated water elevation (light blue shade), and the elevation during a 100 year storm (blue hatch).
More feedback from the pros. We took a site visit to get a raw taste of how rebars are worked on site. Additionally, we asked questions about formworks and concrete pouring. It was interesting to see how the site was arranged in an "assembly line" manner, where one area would be stationed as the rebar cutting, bending, and labeling area. Another area would be cage making, which consists of laying out the rebars, tick marking them, and tying them together. The cages are stacked aside until they are ready for the next, and final station, which is at the location of the pour. This "assembly line" optimizes the routine and enables the contractors to pour a floor slab every 2 days.
Last Thursday after work we took the 7 train out to Shea Stadium where Jess and Tim picked us up and took everyone to the Skanska office where we met with two Skanska executives to discuss construction logistics for our project. It turned out to be a really great meeting. Vince and Shelly have been working in engineering and construction for many years, Vince actually has experience building in Vietnam, so their review of the project was a good reality check. Some of the points they made were:
1. It is a lot easier to plan and design here in an air-conditioned office than out in the field.
3. We need to start getting much more organized in our preparation and planning for construction.
In addition to these themes, they provided us with many ideas and suggestions for building using low-tech methods that can be very effective but are no longer used here in the U.S. It sounded like everyone felt the meeting was extremely valuable despite the fact we all got lost on the way back to the 7 train.
We have been doing more research on the Labyrinth Spillway and it appears that this could be the most cost effective solution to the auxiliary spillway issue.
Brent is looking into the hydraulics of this spillway type, Ryan put together this preliminary design and Jessica will be working on estimating the costs of this configuration and the traditional spillway and water gate.
When the Hydro team finished their study we realized the water gate auxiliary spillway would not be large enough to handle a 100 year flood. Our investigation has shown that the previous failures were due to over-topping so having a adequately sized spillway is certainly a critical aspect of the design. However, when we began looking into typical spillway designs we realized the costs could be much larger than what we have available.
Then Ryan found the Labyrinth Spillway. The idea is that the effective length of the spillway is increased by using a series of trapezoidal or triangular walls instead of a straight wall. This will increase the cost of the water gate but we will save the cost of building an entirely different spillway. There are also potential savings on future maintenance. We are still discussing whether or not this option will be used but it is an interesting idea.
About a month ago we presented our design to the Engineers Without Borders Technical Advisory Committee (TAC) and since then we have been working with them to satisfy their questions and concerns. Early this morning we received our approval! With Human Translations successful fundraiser and this approval we are cleared to begin construction in November when the dry season begins.
Last night Human Translation held a Benefit Concert to raise money for our project and it turned out to be a huge success. We had been increasingly concerned with budget issues as the scope of this project has seemed to grow over the last year. This Benefit Concert was expected to be the largest funding source for this project but I think we were all a little skeptical of the outcome. So for HT to have such a successful event is very exciting and will be a huge help for the project.
Congratulations to Human Translation on all of their hard work putting this great event together!
We submitted our design to the National chapter last month and now we are going through the Technical Advisory Committee (TAC) approval process. The National chapter provides a PowerPoint presentation outline that project teams fill out then present to the TAC. However, our project is a bit larger than the average EWB project so compressing the design into a 20 minute presentation did not really do it justice. The TAC has requested more Geotechnical information so we are creating a response that will answer their questions and hopefully demonstrate that our understanding of the project is much greater than that shown in the short presentation.